U.S. patent number 4,594,426 [Application Number 06/225,820] was granted by the patent office on 1986-06-10 for benzoxazole derivative intermediates for synthesis of dye releasing redox compounds.
This patent grant is currently assigned to Fuji Photo Film Co., Ltd.. Invention is credited to Shinsaku Fujita, Yoshio Inagaki, Koichi Koyama.
United States Patent |
4,594,426 |
Fujita , et al. |
June 10, 1986 |
Benzoxazole derivative intermediates for synthesis of dye releasing
redox compounds
Abstract
Benzoxazole derivatives represented by general formula (I) which
are intermediates for synthesis of o-sulfonamidophenol derivatives
useful as dye releasing redox compounds in a color diffusion
transfer color image forming process: ##STR1## wherein R.sup.1 and
R.sup.2, which may be the same as or different from each other,
each represents an alkyl group or an aryl group or they may combine
and form a ring; R.sup.3 represents a hydrogen atom, an alkyl group
or an aryl group; R.sup.4 represents an alkyl group or an aryl
group; R.sup.5 represents an alkyl group, an alkoxy group, an
alkylthio group, an arylthio group, a halogen atom or an acylamino
group, or --CR.sup.1 R.sup.2 R.sup.3 and R.sup.5 may combine and
form the nucleus ##STR2## which is condensed at the 6- and the
7-positions of the benzoxazole nucleus; and n is 0, 1 or 2.
Inventors: |
Fujita; Shinsaku (Kanagawa,
JP), Koyama; Koichi (Kanagawa, JP),
Inagaki; Yoshio (Kanagawa, JP) |
Assignee: |
Fuji Photo Film Co., Ltd.
(Kanagawa, JP)
|
Family
ID: |
11579647 |
Appl.
No.: |
06/225,820 |
Filed: |
January 16, 1981 |
Foreign Application Priority Data
|
|
|
|
|
Jan 17, 1980 [JP] |
|
|
55-4263 |
|
Current U.S.
Class: |
548/217; 430/218;
430/223; 430/242; 430/380; 430/390; 430/543; 430/552; 430/559;
564/413 |
Current CPC
Class: |
C07D
263/52 (20130101); G03C 8/10 (20130101); C07D
263/56 (20130101) |
Current International
Class: |
C07D
263/00 (20060101); C07D 263/56 (20060101); C07D
263/52 (20060101); G03C 8/10 (20060101); G03C
8/02 (20060101); C07C 093/14 () |
Field of
Search: |
;548/217 ;564/413 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
51-54552 |
|
May 1976 |
|
JP |
|
5610179 |
|
1979 |
|
JP |
|
7910 |
|
1905 |
|
GB |
|
Other References
Fuji Photo Film Co., Ltd., 80/153775, Jap. Chemical Abstract, 94:
175105f. .
Barton et al, "The Synthesis & Reactions of Organic Compounds",
vol. 4, 1979, 971-972. .
McLamore, J. Amer. Chem. Soc., vol. 73, 1951, pp.
2225-2230..
|
Primary Examiner: Lesmes; George F.
Assistant Examiner: Gibson; S. A.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak, and
Seas
Claims
What is claimed is:
1. A benzoxazole represented by formula (II) ##STR17## wherein
R.sup.1 and R.sup.2 may be the same as or different from each
other, and each represents an alkyl group of 1-24 C atoms, a
substituted or unsubstituted phenyl group, a substituted or
unsubstituted naphthyl group, or may combine to form a 5 to 20
membered ring; R.sup.3 represents a hydrogen atom, an alkyl group
of 1-24 C atoms, a substituted or unsubstituted phenyl group or a
substituted or unsubstituted naphthyl group; R.sup.4 represents an
alkyl group of 1-40 C atoms; R.sup.5 represents an alkyl group of
1-40 C atoms, an alkoxy group, or an alkylthio group wherein the
alkyl moiety of said alkoxy or alkylthio group is 1-40 C atoms, a
substituted or unsubstituted phenylthio group or a
1-phenyl-5-tetrazoyl-thio group, a halogen atom or an
alkyl-CONH-group in which the alkyl moiety has from 1-24 C atoms,
or a substituted or unsubstituted phenyl-CONH group, and n is 0, 1,
or 2; the substituents of the substituted group of R, R.sup.2,
R.sup.3 and R.sup.5 being an alkoxy group, a cyano group, a hydroxy
group, a nitro group, or an alkyl group, said benzoxazole
derivative being useful as an intermediate for synthesis of an
o-sulfanamidophenol derivative which acts as a dye releasing redox
compound and provides a transferred dye image having high optical
density when used in a diffusion transfer process.
2. A benzoxazole as in claim 1, wherein R.sup.3 is an alkyl group
of 1-24 C atoms, a substituted or unsubstituted phenyl group or a
substituted or unsubstituted naphthyl group.
3. A benzoxazole as in claim 1, wherein R.sup.1, R.sup.2 and
R.sup.3 are alkyl groups of 1-24 C atoms.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to intermediates for the synthesis of
o-sulfonamidophenol derivatives useful as dye releasing redox
compounds (abbreviated as DRR compounds hereinafter) and
o-aminophenol derivatives useful as developing agents, both of
which can be employed in color photography. More particularly, it
is concerned with intermediates for the synthesis of
o-sulfonamidophenol derivatives which release diffusible dyes by a
redox reaction resulting from development processing of a silver
halide.
2. Development of the Invention
In U.S. Pat. No. 4,076,529 there is described a color diffusion
transfer color image forming process using DRR compounds. The term
"DRR compound" as used therein means a p-sulfonamidophenol (or a
p-sulfonamidonaphthol) compound in which a non-diffusible phenolic
group (or naphtholic group) is bonded to a dye moiety via a
sulfonamido group at its p-position.
However, our research found that the above-described
p-sulfonamidophenols provide a sufficiently high density for a
transferred image only with difficulty. Moreover, since the
above-described p-sulfonamidonaphthols leave p-naphthoquinones in
areas of a light-sensitive element and cause yellow stains even
though the light-sensitive element has been submitted to
desilvering processing after dye release, it is impossible to
utilize the color image remaining on such areas of the
light-sensitive element as negative or positive image.
In Japanese Patent Application (OPI) No. 113624/76,
o-sulfonamidophenols substituted by alkoxyl groups at the
4-position(s) are described as DRR compounds. These compounds
possess rather good properties, compared with conventional DRR
compounds, but they need to be further improved in dye releasing
ability.
In addition, o-sulfonamidophenols having alkoxyl groups and methyl
groups at their 5- and 4-positions, respectively, are described as
DRR compounds in Japanese Patent Application (OPI) No. 149328/78.
However, further improvement upon the dye releasing ability is
required of these o-sulfonamidophenols also.
SUMMARY OF THE INVENTION
Therefore, a first object of the present invention is to provide an
intermediate for producing an o-sulfonamidophenol derivative which
acts as a DRR compound and provides a transferred dye image having
high optical density when used in a diffusion transfer process.
A second object of the present invention is to provide an
intermediate for producing an o-sulfonamidophenol derivative which
acts as a DRR compound and provides, in a light-sensitive element,
a residual dye image with greatly reduced yellow stain.
A third object of the present invention is to provide an
intermediate for producing an o-sulfonamidophenol derivative which
acts as a DRR compound which releases a dye with high
efficiency.
The above-described objects are attained with a compound
represented by the following general formula (I): ##STR3## wherein
R.sup.1 and R.sup.2 may be the same as or different from each
other, and they each represent an alkyl or an aryl group, or they
may combine to form a ring; R.sup.3 represents a hydrogen atom, an
alkyl group or an aryl group; R.sup.4 represents an alkyl group or
an aryl group; R.sup.5 represents an alkyl group, an alkoxyl group,
an alkylthio group, an arylthio group, a halogen atom or an
acylamino group, or R.sup.5 may be bonded to --CR.sup.1 R.sup.2
R.sup.3 to form the nucleus of the structure, ##STR4## which is
condensed at the 6- and the 7-positions of the benzoxazole nucleus;
and n is 0, 1 or 2.
DETAILED DESCRIPTION OF THE INVENTION
In the above-described general formula, the alkyl group represented
by R.sup.1 (and R.sup.2 or R.sup.3) has from 1 to 24, preferably
from 1 to 17, more preferably from 1 to 10, and most preferably
from 1 to 4, carbon atoms. It may be a straight chain, a branched
or a cyclic alkyl group and further, may be substituted (such as an
alkoxyl group, a cyano group, a hydroxy group, a halogen atom, a
phenoxy group, a substituted phenoxy group, an acylamino group or
so on). Preferred examples of the alkyl group represented by
R.sup.1 (and R.sup.2 or R.sup.3) include straight chain alkyl
groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
undecyl, pentadecyl, heptadecyl, etc.; and branched alkyl groups
such as isopropyl, isobutyl, t-butyl, t-amyl, neopentyl, etc.
Examples of the aryl group represented by R.sup.1 (and R.sup.2 or
R.sup.3) include a phenyl group, substituted phenyl groups, a
naphthyl group and substituted naphthyl groups. Examples of the
substituents of these substituted phenyl and napthyl groups include
an alkoxy group, a cyano group, a hydroxy group, a nitro group, an
alkyl group and so on. The ring formed by binding of R.sup.1 to
R.sup.2 is preferably a 5- to 20-membered ring, preferably a 5- to
12-membered ring and most preferably a 6-membered ring. Specific
examples of rings formed with R.sup.1 and R.sup.2 are those in
which R.sup.1 and R.sup.2 are combined together to represent
--(CH.sub.2).sub.x -- wherein x is an integer of 4 to 19; of these,
--(CH.sub.2).sub.x -- wherein x is 5, 6, 7, 9 or 11 is
preferred.
Unless otherwise indicated, the alkyl group or the alkyl moiety
contained in, e.g., alkoxy, has 1 to 10 carbon atoms, preferably 1
to 4 carbon atoms and the acylamino group possesses 2 to 10 carbon
atoms, preferably 2 to 4.
The alkyl group or the alkyl moieties of the alkoxyl group and the
alkylthio group represented by R.sup.5 have 1 to 40, preferably 1
to 24 and more particularly 1 to 4 carbon atoms. They may be
straight chain, branched or cyclic, and may be substituted (e.g.,
alkoxy, cyano, hydroxy, halogen, phenoxy, substituted phenoxy,
acylamino, etc.). As preferred examples of the alkyl group
represented by R.sup.5, mention may be made of those which are
specifically described for R.sup.1.
The arylthio group represented by R.sup.5 is preferably phenylthio,
a substituted phenylthio or a 1-phenyl-5-tetrazolylthio group,
wherein the aryl moiety in the arylthio has 6 to 16 carbon atoms,
preferably 6 to 10 carbon atoms, in total (including substituents,
if present). Most preferably R.sup.5 is a phenylthio or a
substituted phenylthio.
Typical examples of the acylamino group represented by R.sup.5 are
an alkyl-CONH-- group or a (substituted or non-substituted)
phenyl-CONH-- group. In this case the alkyl moiety in the
alkyl-CONH-- has 1 to 24 carbon atoms, preferably 1 to 17 carbon
atoms.
As examples of the substituent in the substituted phenylthio or
phenyl-CONH-- group represented by R.sup.5, mention may be made of
those which are described as specific examples of the substituent
contained in the substituted aryl group represented by R.sup.1 or
R.sup.2.
Examples of the halogen represented by R.sup.5 include fluorine,
chlorine and bromine.
The alkyl group represented by R.sup.4 contains 1 to 40, and
preferably 1 to 24, carbon atoms. It may be straight chain,
branched chain or cyclic. In addition, it may be substituted (e.g.,
alkoxy, cyano, hydroxy, halogen, phenoxy, substituted phenoxy,
acylamino, etc.). Preferred examples of R.sup.1 include straight
chain alkyl groups such as a methyl group, an ethyl group, a propyl
group, a butyl group, a pentyl group, a hexyl group, a heptyl
group, an undecyl group, a pentadecyl group, a heptadecyl group and
the like; and branched chain alkyl groups such as an isopropyl
group, an isobutyl group, a t-butyl group, a t-amyl group, a
neopentyl group and the like.
Examples of the aryl group represented by R.sup.4 include phenyl
group, substituted phenyl groups, naphthyl group, and substituted
naphthyl groups. As examples of the substituents of these
substituted phenyl and naphthyl groups, mention may be made of an
alkoxy group, a cyano group, a hydroxy group, a nitro group, an
alkyl group and so on. Of these groups, a methyl group is
particularly preferred as R.sup.4 from the standpoint of the
facility of preparation.
In a preferred embodiment, the compound of the general formula (I)
exhibits excellent effects in the case that the --OH group and the
--CR.sup.1 R.sup.2 R.sup.3 group present therein occupy the
6-position and the 5-position, respectively, or they occupy the
5-position and the 6-position, respectively, and R.sup.5 is at the
4- and/or 7-position.
In a more preferred embodiment, the OH group and
--C(R.sup.1)(R.sup.2)(R.sup.3) group are attached to the 6- and
5-positions, respectively, and R.sup.5 attached to 4- and/or
7-position, that is, the compounds of the present invention are
represented by the following general formula (II): ##STR5## wherein
R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and n have the same
meanings as those substituents in the general formula (I).
More preferred compounds correspond to the case where R.sup.3 in
general formula (I) or (II) is an alkyl group or an aryl group as
earlier defined.
Still more preferred compounds correspond to the cases where in
general formula (I) or (II), R.sup.1, R.sup.2 and R.sup.3 all are
alkyl groups (which may be the same as or different from one
another), n is 0 or 1 and R.sup.5 is a lower alkyl group having 1
to 4 carbon atoms. Most preferred compounds are represented by the
formula (II) wherein R.sup.1, R.sup.2 and R.sup.3 all are alkyl
groups having 1 to 24 carbon atoms (more preferably 1 to 17 carbon
atoms). Therein, when n is 1, R.sup.5 must be a lower alkyl
group.
Specific examples of the compound of the present invention are
illustrated below: ##STR6##
Compound of formula (I) of the present invention can be synthesized
by the following methods. The substituents R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sub.n.sup.5 represent the same groups as in
formula (I). ##STR7##
A detailed description of Method 1 is given below.
A benzoxazole (I) can be synthesized by allowing an oxime
represented by the general formula (III) to react with phosphorus
oxychloride in the presence of an amide represented by general
formula (V) ##STR8## wherein R.sup.6 represents a hydrogen atom or
an alkyl group containing 1 to 23 carbon atoms; R.sup.7 and R.sup.8
may be the same as or different from each other, and they each
represents an alkyl group having 1 to 24 carbon atoms; or R.sup.6
and R.sup.7, or R.sup.7 and R.sup.8 may combine with each other to
form a ring.
The alkyl group represented by R.sup.6 may be a straight chain or a
branched chain alkyl group. The number of carbon atoms in such a
group is 1 to 23, preferably 1 to 17 and, more particularly, 1 to
4. As examples of the alkyl group, mention may be made of a methyl
group, an ethyl group, a propyl group, an isopropyl group, a butyl
group and the like.
The alkyl group represented by R.sup.7 or R.sup.8 may be a straight
chain or a branched chain alkyl group and it has 1 to 24,
preferably 1 to 18 and, more particularly, 1 to 4 carbon atoms. For
example it can be methyl group, ethyl group, propyl group,
isopropyl group, butyl group or the like.
In addition, when R.sup.6 and R.sup.7, or R.sup.7 and R.sup.8
combine with each other to form a ring (preferably a 5- or a
6-membered ring), the ring formed may contain 1 to 2 hetero atoms
(e.g., oxygen, nitrogen or sulfur) as constituent atom(s). In the
case that R.sup.6 and R.sup.7 combine with each other, an amido
linkage constitutes a part of the ring formed and, consequently, a
ring having an oxy group, such as morpholine-3-one, pyrrolidone,
caprolactam, piperidone, pyrrolidinone or the like, is formed. On
the other hand, in the case that R.sup.7 and R.sup.8 combine with
each other, the amido nitrogen becomes a member of the ring formed
and therefore, a hetero ring such as morpholine, pyrrolidine,
piperidine or the like is formed. Examples of such rings include
for R.sup.6 -R.sup.7 : ##STR9## for R.sup.7 -R.sup.8 :
##STR10##
As the amide represented by the general formula (V),
N,N-dimethylformamide, N,N-dimethylacetoamide and
N-methylpyrrolidone are particularly favorable from the viewpoint
that they are readily available and are inexpensive; they are
miscible with water in all proportions and, therefore,
after-treatment of the reaction solution can be done without
difficulty; and they function as an excellent reaction solvent
because of their high solubility to oxime (III).
In the above-described reaction, the amide represented by formula
(V) functions as a catalyst in the process of the benzoxazole ring
formation through Beckmann rearrangement. It is surmised that the
amide of formula (V) complexes phosphorus oxychloride and the
resulting complex accelerates the ring closure reaction from (III)
to (I).
Method 1 of the present invention is carried out by allowing
phosphorus oxychloride to react with the above-described oxime
(III) in the presence of the amide (V). The reaction can be
generally effected by a simple procedure where oxime (III) and
amide (V) are mixed and then phosphorus oxychloride is added
dropwise to the resulting mixture.
Depending on the solubility of oxime (III), the oxime may be
dissolved in a solvent which does not have any influence on the
reaction, for example, acetonitrile and a catalytic amount of amide
(V) may be added thereto. Typically, the amount of solvent is from
1 to 1,000 parts by weight, preferably from 1 to 100 parts by
weight, and more preferably from 1 to 50 parts by weight, per 1
part by weight of the oxime.
To the thus prepared solution, phosphorus oxychloride is added
dropwise. However, the use of a large amount of amide (V)--both as
a solvent and a catalyst--is superior to the use thereof in a
catalytic amount from the standpoint of simplicity of procedure. In
addition, phosphorus oxychloride may be dissolved in a solvent
having no influence on the reaction (e.g., acetonitrile,
tetrahydrofuran, acetone, sulforan, etc.), and the resulting
solution then be added to the above-described mixture of the oxime
(II) and the amide (V); or the phosphorus oxychloride may be added
as it is without dissolving it in any solvent. The amount of the
solvent used for dissolving phosphorus oxychloride is thus
generally in a range of 0 to 100, preferably 0 to 50 parts by
weight, per 1 part by weight of phosphorus oxychloride; wherein "0"
means a case where no solvent is used and accordingly phosphorus
oxychloride is dropwise added as is without dilution.
The amount of amide (V) to be used in the Method 1 of the present
invention does not have any upper limit for the above-described
reason. Therefore, amide (V) is basically used in a catalytic
amount or more, more specifically, in an amount of about 0.01 mol
or more, preferably about 0.1 mol or more and particularly about 1
mol or more, to 1 mol of oxime (III).
In Method 1 of the present invention, phosphorus oxychloride is
used in an amount of about 0.3 to 20 mols, preferably about 0.3 to
5 mols, per 1 mol of oxime (III).
Since the above-described reaction proceeds quickly at a low
temperature, the reaction temperature is not restricted to any
special range. However, it is desirable that the reaction
temperature is set within the range of about -78.degree. C. to
about 200.degree. C., preferably about 0.degree. to 100.degree. C.,
more particularly, about 0.degree. to 40.degree. C. In the event
that the reaction of the present invention is exothermic and the
temperature of the reaction system rises beyond 40.degree. C., the
reaction system should be cooled so that the reaction temperature
is maintained within the above-described temperature range. In
particular, on the occasion that R.sup.6 in the amide (V) is
hydrogen, the temperature of the reaction system must be maintained
at a temperature of 40.degree. C. or lower in order to prevent side
reactions from occurring.
The reaction is usually run at ordinary pressure, but it can be
also conducted under increased pressure or reduced to a small
extent, i.e., reduced pressure is from 1 to 760 mg/Hg, preferably
10-760 mg/Hg, and elevated pressure: 1-50 kg/cm.sup.2, preferably
1-10 kg/cm.sup.2 ; most preferred is normal pressure.
The time spent in dropwise adding phosphorus oxychloride is
selected depending upon the reaction temperature, the kind of the
oxime used as a starting material, the reaction scale and so on. As
indicated above, the reaction is exothermic, and in the event that
the temperature rises higher than a certain maximum temperature,
e.g., about 40.degree. C. (optimum reaction temperature depends
upon compounds used), undesired side-reactions might occur. Thus,
the addition rate of phosphorus oxychloride is controlled such that
the temperature does not exceed the maximum temperature, which
would in turn regulate the time spent in the dropwise addition of
phosphorus oxychloride. Usually, it is set within the range of
about 30 minutes to about 3 hours. At the conclusion of the
dropwise addition of phosphorus oxychloride the reaction proceeds
in an instant and goes to completion in most cases. By way of
precaution, the reaction system may be left for additional 30
minutes to 2 hours as it is and the reaction thereby
terminated.
After the reaction is completed, the reaction mixture is usually
cooled to room temperature by being allowed ty stand for time and,
then, poured into ice water. By this treatment, a precipitate
separates out. The resulting precipitate is filtered off and is
recrystallized from a proper solvent such as benzene, alcohol or
the like in a conventional manner. Thus, the desired benzoxazole
(I) is obtained.
In the above-described purification of the reaction product, an
operation where the contents are poured into ice water are
neutralized with a proper alkali, e.g., sodium acetate, sodium
bicarbonate, sodium carbonate, sodium hydroxide, etc., whereby the
resulting solution comes to have a pH value of about 4 to about 7,
may be further added with the intention of improving filtering
efficiency regarding the filtration of precipitates and discharging
the filtrate in a safe form.
The Beckmann rearrangement for the conversion of (III) into (I)
proceeds even in the presence of a hydrogen chloride-acetic acid
mixture and also using a Lewis acid, a Bronsted acid, an acid
anhydride or an acid halide in the place of phosphorus oxychloride
in the presence of the amide of formula (V).
The above-described Lewis acid used in combination with the amide
of formula (V) is represented by the general formula (A):
wherein A is a Lewis acid group and X is a halogen atom,
particularly chlorine or bromine.
As examples of the Lewis acid which functions effectively as the
Lewis acid of the present invention, mention may be made of:
Sulfur atom-containing Lewis acids:
wherein Y.sup.1 represents a halogen atom, or an unsubstituted or
substituted phenyloxy group and X represents a halogen atom;
wherein Y.sup.2 represents an alkyl group, an unsubstituted or
substituted phenyl group or a halogen atom; and X represents a
halogen atom;
Phosphorus atom-containing Lewis acids:
wherein Y.sup.3 and X each represents a halogen atom, and it is
preferable for them to represent the same halogen atom; and
Carbon atom-containing Lewis acids:
wherein Y.sup.4 represents an unsubstituted or substituted
phenyloxy group, a halogen atom or X--CO-- where X represents a
halogen atom.
Examples of the substituent of the substituted phenyl group
represented by Y.sup.1 include a halogen atom, preferably Cl or Br,
nitro group, cyano group, an alkoxy group, an alkyl group and so
on.
The halogen atom represented by Y.sup.1 is chlorine or bromine.
The alkyl group represented by Y.sup.2 contains 1 to 8, preferably
1 to 4, carbon atoms, and it may be a straight chain or a branched
chain alkyl group and further may be a cyclic alkyl group. The most
preferable alkyl group represented by Y.sup.2 is a methyl
group.
Examples of the substituent of the substituted phenyl group
represented by Y.sup.2 include a halogen atom, particularly
chlorine, nitro group, cyano group, an alkoxy group, an alkyl group
and so on.
Representative of the halogen atoms represented by Y.sup.3 are
chlorine and bromine.
Examples of the substituent of the substituted phenyloxy group
represented by Y.sup.4 include a halogen atom, particularly
chlorine, nitro group, cyano group, an alkoxy group, an alkyl group
and so on.
A particularly favorable example of the halogen atom represented by
Y.sup.4 is chlorine.
Specific examples of the Lewis acid which can be used in a still
more preferred embodiment of the present invention are thionyl
chloride (SOCl.sub.2) when selected from those represented by
formula (Aa); methanesulfonyl chloride (CH.sub.3 SO.sub.2 Cl),
p-toluenesulfonyl chloride, p-chlorobenzenesulfonyl chloride, m-
and p-nitrobenzenesulfonyl chlorides and sulfuryl chloride
(SO.sub.2 Cl.sub.2) when selected from those represented by formula
(Ab); POCl.sub.3 and POBr.sub.3 when selected from those
represented by formula (Ac); PCl.sub.3 and PBr.sub.3 when selected
from those represented by formula (Ad); PCl.sub.5 when selected
from those represented by formula (Ae); phenyl chloroformate when
selected from those represented by formula (Af); phosgene and
oxalyl chloride; and so on.
The Lewis acid method of synthesis can generally be effected by a
simple procedure where oxime (III) and amide (V) are mixed and then
the Lewis acid (A) is dropped into or added to the resulting
mixture. Depending on the solubility of oxime (III), the oxime may
be dissolved in a solvent having no influence on the reaction, such
as acetonitrile or the like, and the amide added thereto. To the
resulting solution, the Lewis acid is dropwise added. Amide (V) may
be added in a large amount both as a reacting species and a
solvent. In addition, the Lewis acid (A) may be dissolved in a
solvent having no influence on the reaction and the resulting
solution then be added to the above-mentioned mixture or the Lewis
acid (A) may be added as is.
The amount of amide (V) to be used in the present invention does
not have any upper limit for the above-described reason. Therefore,
amide (V) is used basically in a catalytic amount or more, and,
specifically, in an amount of about 0.001 mol or more, preferably
about 0.01 mol or more and, particularly, about 1 mol or more, per
1 mol of the oxime (III). I.e., reduced pressure is from 1 to 760
mg/Hg, preferably 10 to 760 mg/Hg, and elevated pressure is from 1
to 50 kg/cm.sup.2, preferably 1 to 10 kg/cm.sup.2 ; most preferred
is normal pressure.
The amount of Lewis acid (A) used in the present invention is
generally within the range of about 0.3 to 20 mols, preferably
within the range of about 0.3 to 5 mols and, more particularly,
within the range of about 1 to 5 mols, per 1 mol of oxime (III). As
indicated above, the reaction is exothermic, and in the event that
the temperature rises higher than a certain maximum temperature,
e.g., about 40.degree. C. (optimum reaction temperature depends
upon compounds used), undesired side-reactions might occur. Thus,
the addition rate of phosphorus oxychloride is controlled such that
the temperature does not exceed the maximum temperature, which
would in turn regulate the time spent in the dropwise addition of
phosphorus oxychloride.
Since the above-described reaction of the present invention
proceeds quickly at a low temperature under ordinary circumstances,
there is no special limit to the reaction temperature. However, it
is desirable that the reaction temperature be set within the range
of about -78.degree. C. to about 200.degree. C., preferably about
0.degree. C. to about 100.degree. C. and, more particularly, about
0.degree. C. to about 40.degree. C. In the event that the reaction
is an exothermic reaction and the temperature of the reaction
system rises beyond 40.degree. C., the reaction system should be
cooled and maintained at a temperature within the above-described
range. In particular, on the occasion that R.sup.6 in amide (V) is
hydrogen, the temperature of the reaction system must be maintained
at a temperature not higher than 40.degree. C. in order to prevent
side reactions from occurring. Contrary to the above, the reaction
system may be heated to accelerate the reaction in the case that
R.sup.6 is an alkyl group.
The reaction is usually run under an ordinary pressure, but it can
be also conducted under increased pressure or reduced to a small
extent.
The time spent in dropping or adding Lewis acid (A) is selected
depending upon the reaction temperature, the kind of the oxime used
as a starting material, the reaction scale and so on. Usually, it
can be set within the range of about 30 minutes to about 3 hours.
In most cases, at the conclusion of the dropping or adding
procedure, the reaction proceeds in an instant and goes to
completion. By way of precaution, the reaction system may be left
for additional 30 minutes to 2 hours as it is, whereby the reaction
is terminated completely.
After the reaction is completed, the reaction mixture is usually
cooled to room temperature by being allowed to stand for a time
and, then, poured into ice water. By this treatment, a precipitate
separates out. The resulting precipitate is filtered off and is
recrystallized from a proper solvent such as benzene, an alcohol or
so on. Thus, the desired benzoxazole (I) is obtained.
To the above-described separation steps, an operation where the
reaction contents poured into ice water are neutralized with an
appropriate alkali, e.g., sodium acetate, sodium bicarbonate,
sodium carbonate, sodium hydroxide, etc., whereby the resulting
solution comes to have a pH value of about 4 to about 7, may be
added for the purposes of improvement of filtering efficiency of
the precipitates and safe discharge of the filtrate.
In accordance with the method for synthesis in the present
invention wherein a Lewis acid and an amide are used as reacting
agents, benzoxazole derivatives can be obtained in high yield under
mild reaction conditions and through a simple procedure. Further,
even oximes which are subject to decomposition at high temperatures
(for example, 2,5-dihydroxyacetophenone oxime derivatives) can be
employed as a starting material because the reaction proceeds at a
low temperature. Therefore, the synthesis method of the present
invention is very useful.
The ring closure reaction of above Method 2 can be effected by
working up the compound of rormula (IV) in the presence of an acid
catalyst such as p-toluenesulfonic acid where p-toluenesulfonic
acid us used in an amount of 0.01 mol to 1 mol, preferably 0.1 mol
to 0.3 mol, per 1 mol of the compound represented by formula
(IV).
The solvent employed for the reaction is selected depending upon
the solubility of the compound of formula (IV) therein. The solvent
is generally used in an amount of from 1 to 1,000, preferably from
1 to 100, and more preferably from 1 to 50 parts by weight, per 1
part by weight of (IV). Examples of such a solvent include aromatic
hydrocarbon series solvents, e.g., benzene, toluene, xylene, etc.;
alcohol series solvents, e.g., ethanol, n-butanol, isopropyl
alcohol, etc.; halogenated hydrocarbon series solvents, e.g.,
1,1,1-trichloroethane, 1,2-dichloroethane, etc.; and ester series
solvents, e.g., ethyl acetate, etc. The reaction temperature is set
within the range of about 0.degree. C. to about 200.degree. C.,
preferably about 50.degree. C. to 150.degree. C. The reaction time
is usually set within the range of about 1 hour to about 24 hours.
I.e., reduced pressure is from 1 to 760 mg/Hg, preferably 10 to 760
mg/Hg, and elevated pressure is from 1 to 50 kg/cm.sup.2,
preferably from 1 to 10 kg/cm.sup.2 ; most preferred is normal
pressure.
The ring closure reaction of Method 2 can also be conducted using
the combination of phosphorus oxychloride with amide (V) as a
reacting agent. Namely, benzoxazole (I) can be produced by the
reaction of the compound represented by formula (IV) with
phosphorus oxychloride in the presence of the amide represented by
formula (V). In general, benzoxazole (I) can be synthesized by the
simple procedure that compound (IV) and amide (V) are mixed and
phosphorus oxychloride is added dropwise thereto. Preferred
addition amounts of phosphorus oxychloride, reaction temperatures,
reaction times, solvents and after-treatment methods are the same
as those hereinbefore described for Method 1.
Oxime (III) which is the starting material in Method 1 can be
synthesized by the following process: ##STR11##
In Process I, the compound represented by formula (VI) is subjected
to acetylation of its nucleus, for example, by the combined use of
BF.sub.3 and acetic acid to obtain compound (VII) and then
resulting compound (VII) is reacted with hydroxylamine to produce
oxime (III). Source compound (VI) is commercially available.
A representative method for the synthesis of compounds represented
by formula (IV) is illustrated below using an easy to scan reaction
scheme. Specifically, the reaction process is described using as a
representative example resorcinol derivative (IV'). However, the
positions of the OH substituent, the --R.sub.n.sup.5 substituent
and the --CR.sup.1 R.sup.2 R.sup.3 substituent are not intended to
be construed as beling limited to those in this example.
##STR12##
The description of Process II is as follows: resorcinol derivative
(VIII) is subjected successively to nitrosylation, reduction and
acetylation to result in conversion into compound (IV'). Other
derivatives of formula (IV), i.e., catechol type (o-dehydroxy
type), hydroquinone type (p-dehydroxy type), can be prepared by
subjecting catechol or hydroquinone type compounds corresponding to
(VIII) (wherein only a relative position of two OH groups is
different) to acetylation, nitration, reduction and an acid
treatment, in turn, in a conventional manner to obtain compound
(IV). Each of these steps can be practiced using the procedure for
the preparation of 2-acetoamido-4-cyclohexylresorcinol using
4-cyclohexylresorcinol as a starting material as described in W. M.
McLamore, J. Amer. Chem. Soc., Vol. 73, pp. 2225-2230 (1951).
Source compound (VIII) is commercially available.
The compounds of this invention can be used in various photographic
elements, as described, e.g., in U.S. Pat. No. 4,076,529, and in
Research Disclosure, No. 151, 15162, November 1976.
A preferred process for producing a photographic transfer image in
color using these compounds comprises the steps of:
(1) Treating an imagewise exposed photosensitive element of the
invention with an alkaline processing composition in the presence
of a silver halide developing agent to reflect development of the
silver halide emulsion layers as a function of exposure, thereby
oxidizing the developing agent and the oxidized developing agent in
turn cross-oxizing the dye redox releasing compound;
(2) Forming an imagewise distribution of diffusible released dye as
a function of the development of the silver halide emulsion layers
by cleaving, under alkaline conditions, cross-oxidized dye redox
releasing compounds; and
(3) Diffusing out of the layer in which the dye redox releaser was
coated at least a portion of the imagewise distributions of
diffusible released dye.
Typical examples of some of the compounds of the present invention
are illustrated in detail below.
EXAMPLE 1
Synthesis of Compound 1
In a mixture of 30 ml of N,N-dimethylacetamide and 30 ml of
acetonitrile was dissolved 11 g of
5'-t-butyl-2',4'-dihydroxyacetophenone oxime. To the resulting
solution, which was cooled on an ice bath with stirring, was
dropwise added 20 ml of phosphorus oxychloride over a period of 30
minutes. The reaction mixture continued to be stirred for an
additional 30 minutes as it was and, then, 200 mol of ice water was
gradually added thereto over a period of an hour. The crystals thus
precipitated were recovered by filtration, and 50 g of
5-t-butyl-2-methyl-6-benzoxazolol (Compound 1) was obtained. Yield
85%, Melting Point 264.degree. to 266.degree. C.
EXAMPLE 2
Synthesis of Compound 2
In the same manner as described in Example 1 except that
5'-t-amyl-2',4'-dihydroxyacetophenone oxime was used in place of
5-t-butyl-2,4-dihydroxyacetophenone oxime,
5-t-amyl-2-methyl-6-benzoxazolol (Compound 2) was obtained. Yield
62%, Melting Point 237.degree. to 238.degree. C.
EXAMPLE 3
Synthesis of Compound 3
In the same manner as described in Example 1 except that
2',4'-dihydroxy-5'-(1-ethyl-1-methylpropyl)acetophenone oxime was
used in place of 5'-t-butyl-2',4'-dihydroxyacetophenone oxime,
5-(1-ethyl-1-methylpropyl)-6-benzoxazolol (Compound 3) was
obtained. Yield 87%, Melting Point 217.degree. to 218.degree.
C.
EXAMPLE 4
Synthesis of Compound 8
In the same manner as described in Example 1 except that
5'-t-butyl-2',4'-dihydroxy-3'-methylacetophenone oxime was used in
place of 5-t-butyl-2,4-dihydroxyacetophenone oxime,
5-t-butyl-2,7-dimethyl-6-benzoxazolol (Compound 8) was obtained.
Yield 85%, Melting Point 166.degree. to 168.degree. C.
EXAMPLE 5
Synthesis of Compound 10
In the same manner as described in Example 1 except that
2-acetyl-5-t-butylhydroquinone oxime was used in place of
5'-t-butyl-2',4'-dihydroxyacetophenone oxime,
6-t-butyl-2-methyl-5-benzoxazolol (Compound 10) was obtained. Yield
88%, Melting Point 203.degree. to 205.degree. C.
EXAMPLE 6
Synthesis of Compound 12
In the same manner as described in Example 1 except that
2-acetyl-5,8-methano-5,6,7,8-tetrahydro-1,4-naphthohydroquinone
oxime was used in place of 5'-t-butyl-2',4'-dihydroxyacetophenone
oxime, Compound 12 was obtained. Yield 89%, Melting Point
259.degree. to 260.degree. C.
EXAMPLE 7
In the same manner as described in Example 1 except that thionyl
chloride was used in place of phosphorus oxychloride, Compound 1
was obtained with a yield of 80%.
EXAMPLE 8
In the same manner as described in Example 1 except that
methanesulfonyl chloride was used in place of phosphorus
oxychloride, Compound 1 was obtained with a yield of 72%.
EXAMPLE 9
In the same manner as described in Example 1 except that phenyl
chloroformate was used in place of phosphorus oxychloride, Compound
1 was obtained with a yield of 75%.
EXAMPLE 10
In the same manner as described in Example 1 except that oxalyl
chloride was used in place of phosphorus oxychloride, Compound 1
was obtained with a yield of 80%.
EXAMPLE 11
In the same manner as described in Example 6 except that thionyl
chloride was used in place of phosphorus oxychloride, Compound 12
was obtained with a yield of 86%.
EXAMPLE 12
In the same manner as described in Example 1 except that
2',5'-dihydroxy-6'-t-butylacetophenone oxime and thionyl chloride
were used instead of 5'-t-butyl-2',4'-dihydroxyacetophenone oxime
and phosphorus oxychloride, respectively, the desired
2-methyl-5-hydroxy-6-t-butylbenzoxazolol was obtained. Yield 83%
(light brown needles), Melting Point 203.degree. to 205.degree.
C.
COMPARATIVE EXAMPLE
A mixture consisting of 3 g of
2,5-dihydroxy-3,4-dimethylacetophenone oxime and 12 ml of formic
acid was refluxed for 3 hours. However,
2,6,7-trimethyl-5-hydroxybenzoxazole was not produced at all. The
experiment discussed hereinabove was a duplication of Japanese
Patent Application (OPI) No. 54552/76.
DRR compounds useful in a color diffusion transfer process can be
synthesized using the compounds of the present invention as
intermediates. Representative DRR compounds are the compounds
represented by the following general formula (XI): ##STR13##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.5 and n have the same
meanings as in the formula (I), respectively; G represents hydroxy
group or a group capable of providing a hydroxy group by
hydrolysis; Col represents a dye (e.g., cyan, magenta or yellow
dye) residue or a dye precursor residue; and R represents an alkyl
group or an aryl group, which is preferably a ballast group.
Specific examples of G include a hydroxy group; groups represented
by the formula, alkyl-COO-, wherein 2 to 40, preferably 2 to 8, and
more particularly, 2 to 4, carbon atoms are contained (e.g.,
acetoxyl, propionyloxy, etc.); and aromatic carbonyloxy groups
having 6 to 40, preferably 6 to 15, and more particularly, 6 to 9,
carbon atoms (e.g., benzoyl, substituted benzoyls, etc.).
Examples of Col include azo dye residues, azomethine dye residues,
indoaniline dye residues, indophenyl dye residues, triphenylmethane
series dye residues, anthraquinone dye residues, indigo series dye
residues and their metal complex salt residues. In addition, Col
includes those compounds which can produce the above-described dye
residues by hydrolysis; for example, dye
Japanese Patent Application No. 125818/73 (corresponding to OPI No.
78327/75, U.S. Pat. Nos. 3,222,196 and 3,207,947.) See also
Japanese Patent Application (OPI) Nos. 33826/73, 114424/74, and
126332/74.
As compared with conventional DRR compounds, DRR compounds having
general formula (XI) which are obtained using the compounds of the
present invention possess the following advantages:
(i) They release dyes with high efficiency and, therefore, the
amount used can be reduced.
(ii) Accordingly, the thickness of a layer containing the DRR
compound can be reduced and the time required for image finishing
can be shortened.
(iii) As a consequence of the decrease in the amount used, the
amount of alkali and developing agent contained in a processing
solution can be decreased.
(iv) As a consequence of the decrease in the amount used, an amount
of a color-mixing preventing agent incorporated into an interlayer
can be reduced. This leads to thinning of the interlayer thickness
and contributes to shortening image finishing time.
(v) As a consequence of the decrease in the amount used, the amount
of a dispersing solvent can be reduced.
(vi) As a consequence of the decrease in the amount used, the
amount of silver halide emulsion can be reduced. This leads to a
thinning of the emulsion layer and contributes to shortening the
image finishing time.
(vii) They can provide sufficiently high transferred image density
(D.sub.max) and sufficiently low D.sub.min.
(viii) Gradation of foot part is hard and, therefore, they are used
to advantage in view of color reproducibility.
Further, of the DRR compounds having general formula (XI) those
which have such the particular configuration where the R.sup.1
R.sup.2 R.sup.3 C-- group occupies the 4-position and the R--O--
group occupies the 5-position to the substituent G are of great
importance and have the following advantages, as compared with DRR
compounds having the configuration where the R.sup.1 R.sup.2
R.sup.3 C-- group occupies the 5-position and the R--O-- group
occupies the 4-position:
(ix) The former DRR compounds can be used in combinations with
developing agents having lower half-wave potentials (and
consequently, higher developing speeds). Therefore, image forming
time can be shortened.
(x) The former DRR compounds crystallize and separate out of their
solutions more slowly. Therefore, emulsions containing the former
DRR compounds have high stabilities.
Particularly favorable DRR compounds obtained by the use of the
intermediates of the present invention are represented by the
following general formula (XII): ##STR14## wherein R.sup.1,
R.sup.2, R.sup.3, R, R.sup.5, n and Col have the same meanings as
in formula (XI).
Specific examples of the DRR compound represented by the general
formula (XI) are illustrated below. ##STR15##
Preparation of the DRR compound represented by the general formula
(XI) from the compound (I) of the present invention can be effected
according to the following process: ##STR16## wherein Hal
represents a halogen atom and other moieties have the same meanings
as in the formula (XI).
Namely, in order to obtain compound (XIII) through O-alkylation of
compound (I), R--Hal is used and, further, a basic material such as
sodium alkoxide or potassium carbonate is used as a hydrogen halide
extracting agent.
Next, compound (XIII) is treated with an acid such as diluted
hydrochloric acid, whereby the oxazole ring is opened. Thus,
compound (XIV) is obtained.
Methods for the synthesis of the dye moiety and its sulfonyl halide
(XV) are described in Japanese Patent Application (OPI) Nos.
12581/73, 33826/73, 114424/74, 126332/74 and so on.
In general, it is preferred to conduct the condensation reaction of
compound (XI) and compound (XV) in the presence of a basic
material. Specific examples of such basic materials include
hydroxides of alkali metals or alkaline earth metals (e.g., sodium
hydroxide, potassium hydroxide, barium hydroxide, calcium
hydroxide, etc.), aliphatic amines (e.g., triethylamine, etc.),
aromatic amines (e.g., N,N-diethylaniline, etc.), heterocyclic
aromatic amines (e.g., pyridine, quinoline, .alpha.-, .beta.- or
.gamma.-picoline, lutidine, collidine,
4-(N,N-dimethylamino)pyridine, etc.), and heterocyclic bases (e.g.,
1,5-diazabicyclo[4,3,0]nonene-5, 1,8-diazabicyclo[5,4,0]undecene-7,
etc.). In the case Hal=Cl, namely in the case that formula (XV)
represents sulfonyl chloride, heterocyclic aromatic amines
(particularly pyridine) are superior to other basic materials
described above.
An example of the synthesis of a DRR compound using the
intermediate of the present invention is illustrated in detail
below.
REFERENCE EXAMPLE
Synthesis of Compound DRR-1
(a) Synthesis of 2-amino-4-t-butyl-5-hexadecyloxyphenol
hydrochloride
In 30 ml of N,N-dimethylformamide were dissolved 10.5 g of
5-t-butyl-2-methyl-6-benzoxazole and 15 g of hexadecyl bromide. To
the resulting solution, 10 g of potassium carbonate was added. The
reaction mixture was stirred and heated to 90.degree. C. Then, it
was poured into ice water, and the oily material thus separated out
was extracted with ethyl acetate. Anhydrous sodium sulfate was
added to the resulting extract to dry the extract. The desiccated
extract was filtered and concentrated. The thus obtained residue
was dissolved in 120 ml of ethanol and 96 ml of 35% hydrochloric
acid, and refluxed under heat. Crystals separated out and were
recovered by filtration. Thus, 12 g of the above-described compound
was obtained.
(b) Synthesis of Compound DRR-1
To 20 ml of N,N-dimethylacetoamide were added 4.4 g of
2-amino-4-t-butyl-5-hexadecyloxy-phenyl hydrochloride and 4.6 g of
3-cyano-4-(4-methoxyethoxy-5-chlorosulfonylphenylazo)-1-phenyl-5-pyrazolon
e. To the resulting mixed solution was dropwise added 4.7 ml of
pyridine with stirring. After the conclusion of dropwise addition,
stirring was continued for additional 2 hours at a room
temperature. Then, 30 ml of methanol and 10 ml of water were added
to the reaction mixture to result in the separation of an oily
material. By the addition of about 20 ml of ethanol to the oily
material, crystals separated out. The crystals were recovered by
filtration. Yield 4.8 g.
While the invention has been described in detail and with reference
to specific embodiments thereof, it will be apparent to one skilled
in the art that various changes and modifications can be made
therein without departing from the spirit and scope thereof.
* * * * *